JSFiddle - React, Tailwind, and code Playground

HTML

<div id="application_osx">foo</div>

JavaScript

var StyleWriter = new Class({
    // css classes on the fly, based on by Aaaron Newton's version
    createStyle: function(css, id) {
        try {
            if ($(id) && id) return;
            
            var style = new Element('style', {id: id||'',type:'text/css'}).inject(document.getElement('head'));
            
            
            if (window.ie)
                style.styleSheet.cssText = css;
            else
                style.setHTML(css);
            
        } catch(e) {
            console.log("failed:", e.message);
        }
    }
});
                            
var rules = [
    "#application_osx { background: red url(/path/to/image/application_osx.png) }",
     "#someotherid { background: url(/path/to/image/someotherid.png) }"
];

// direct use through class
(function() {                           
    new StyleWriter().createStyle(rules.join("\n"), "mystyles");
}).delay(2000); // wait 2 sec then add css rules